Passenger boarding bridges have numerous applications such as connecting an airplane to an airport terminal or a ship to a dock. One type of passenger boarding bridge is an extensible bridge, which has a variable length to accommodate varying distances between passenger departure points and the ship or airplane. Some extensible bridges have a fixed end and a free end. In those types of bridges, the bridge may be rotated about the fixed end while the bridge is maintained at a constant length. In such a case, the free end travels along a circular path. In addition, the bridge may also extend at the free end while rotating, thus providing a non-circular path of travel for the free end. Rotation and extension enables the free end to be positioned at a desired point along the dock or airport terminal. Both rotating and extending are generally accomplished through steering two sets of drive wheels positioned on the free end. To stabilize the bridge, the two sets of wheels are often separated by a large distance, but are nevertheless each steered in the same direction based the direction of travel of the free end. These wheels often skid during rotation and extension causing wear of the wheels and damage to the bridge.
This problem of skidding has been previously addressed in bridges that do not extend in length, which are sometimes called radial bridges. In radial bridges, the free end of the bridge swings in a fixed arc. Skidding of the wheels is reduced through separately aligning each set of wheels in a predetermined and fixed direction. However, this method of preventing skidding does not address skidding of wheels in a bridge that may extend as well as rotate. Therefore, a need has arisen for a new method and apparatus that overcomes the disadvantages and deficiencies of the prior art.